Shaft drill safety device



Sept. 5, 1939. N ws 2,172,088

SHAFT DRILL SAFETY DEVICE Filed July 15, 1958 INVENTOR. Ja/m 5. Nan 50m ATTORNEY.

Patented Sept. 5, 1939 v UNITED STATES PATENT OFFICE SHAFT DRILL SAFETY DEVICE John Branner Newsom, Nevada City, cane, as-

signor to Idaho Maryland Mines Corporation, San Francisco, Calif., a corporation of Nevada Application July 15, 1938, Serial No. 219,422

3 Claims. (01. 255-4 This invention relates in general to a shaft drill Figure 3 is a diagrammatic illustration of the such as for example shown in my Patent 2,090,304 limit switch and electric circuit used in carrying of August 17, 1937, and in particular to a safety out the objects of my invention. device applicable thereto. As generally shown in Figures 1 and 2 and 5 The shaft core drill as disclosed in my patent more specifically shown and described in my 5 above referred to comprises in general a comaforesaid patent, my invention is embodied in partment or pilot house for accommodating an a shaft drill comprising a pilot house I provided electric motor and an operator. Extending with suitable wall jacks or screws 2 for securing downwardly through this pilot house is a shaft it in any predetermined position within the mine operated by said motor and carrying at its lower shaft or bore 3. Extending through the pilot 10 end a core drill. The pilot house is provided with house I is a drive shaft 4 carrying at its lower wall jacks or screws by which it may be secured end the core drill 5. Disposed within the pilot in any predetermined position within the shaft, house I is an electric motor 6 arranged by suitnot only against the action of gravity but able gearing to rotate the drive shaft 4 and conagainst the torque resulting from the rotation of nested by leads I and 8 to a source of electric 15 the core drill against the resistance of the bottom power not shown. Inserted in the lead I of the of the shaft. In operating a core drill of this input to the motor 6 is a limit switch 9 secured type, it has been found that on several occasions to the pilot house I. The limit switch 9 comthe wall jacks or screws have pulled loose or that prises a fixed contact I2 and a movable contact I2 the motor was put into operation before the wall secured to one end of a lever I3. The lever I3 is 20 jacks were properly tightened. Since the core pivoted intermediate its ends to the switch housdrill operates against the resistance of the boting and is provided with a spring M- which serves tom of the shaft, the torque between the drive normally to hold the contacts II and I2 out of shaft and the motor was converted into rotary engagement. The free end of the lever I3 exmotion of the pilot house. The pilot house oontends through the switch housing and is provided 25 tinued to rotate until the electric wires leading with a recess l5. In its operative position, the to the motor were broken, and as a consequence contacts II and I2 are held in their closed posiof the rotary motion of the pilot house, the option against the action of the spring I4 by a pin erator was thrown against its inner wall. Fortu- I6, one end of which is accommodated in the nately in these instances, and contrary to all rules recess I5 while the other end extends through an 30 of probability, the operator within the pilot house opening I! formed in the wall of the pilot house was not seriously injured. I and engages the wall of the bore 3. The pin In general, the object of this invention is the I6 if desired may be secured to the pilot house I provision of a switch in the power input to the by a chain I8.

motor operating the drive shaft, and which is ar- It will be noted from the above description 35 ranged to open automatically upon any relative that after the pilot house I is secured in any movement between the pilot house and the shaft predetermined position within the mine shaft or or bore in which it is disposed. bore 3 by the wall jacks or screws 2 and the pin The invention possesses other advantageous I6 is inserted in its operative position as shown features, some of which with the foregoing will in Figure 2, any relative motion between the pilot 40 be set forth at length in the following description house and the bore 3 will serve to trip the pin l6 where that form of the invention which has been and thereby permit the spring Hi to move the selected for illustration in the drawing accomcontact I I out of engagement with the contact panyin'g and forming a part of the present speci- I2, to thereby stop the motor. It is to be further fication is outlined in full. In said drawing, one noted that since the limit switch is normally held 45 form of the invention is shown, but it is to be in its open position by the spring M, the motor 5 understood that it is not limited to such form, can not be started until the pin I6 is propped since the invention as set forth in the claims between the lever l3 and. the bore 3. may be embodied in a plurality of forms. I claim;

Referring the drawing: l. A device for drilling a bore comprising: a 50 Figure 1 is Vertical mid-Section taken motor compartment; means for detachably sethrough a core drill disposed in a mine shaft or curing d ompartment i any predetermined bo e a d emb y the O j of y inVeHtiOnposition within said bore; a drive shaft depend- Figure 2 is a section taken on the line 2--2 of ing from said compartment and secured at its Figure 1. lower end to a drill; a motor carried by said 55 compartment for rotating said drive shaft; and means associated with said compartment and responsive to relative movement between said compartment and said bore for causing said motor to become inoperative with respect to said drive shaft.

2. A device for drilling a bore comprising: a motor compartment; means for detachably securing said compartment in any predetermined position within said bore; a drive shaft depending from said compartment and secured at its lower end to a drill; an electric motor carried by said compartment for rotating said drive shaft; a switch carried by said compartment in circuit with the power input to said motor; and means responsive to relative movement between said compartment and said bore for tripping said switch.

3. A device for drilling a bore comprising: a motor compartment; means for detachably securing said compartment in any predetermined position within said bore; a drive shaft depending from said compartment and secured at its lower end to a drill; an electric motor carried by said compartment for rotating said drive shaft; a switch carried by said compartment in circuit with the power input to said motor; a spring for urging said switch to its open position; and means operating against the action of said spring for maintaining said switch in its closed position so long as there is no relative motion between said compartment and said bore and for opening said switch upon relative motion between said compartment and said bore.

JOHN BRANNE-R NEWSOM. 

